Breast pumps are well known, and are generally comprised of a hood that fits over the breast, a vacuum pump connected to the hood for generating an intermittent vacuum (or negative pressure) within the hood, and a receptacle for expressed milk. The intermittent suction action of the vacuum pump serves to pull on the breast and nipple and thereby extract milk in an action reminiscent of suckling. The milk so extracted typically flows from the hood into a collection container for storage and later use. A breast pump of the foregoing type is shown in Larsson, U.S. Pat. No. 4,857,051, the disclosure of which is incorporated herein by reference.
Also disclosed in U.S. Pat. No. 4,857,051 is a rigid insert designed to decrease the cross-sectional area of the hood for use of the breast pump with smaller breasts. Soft inserts in breast pumps are also known in the art, as disclosed by U.S. Pat. No. 4,799,922. A drawback of many soft inserts is their tendency to pinch the nipple as the insert contracts under vacuum, causing discomfort and irritation.
A light stroking or squeezing of the sides of the nipple during lactation, however, enhances the expression of milk. Such action is more akin of the suckling of an infant.